From 28c0f0f4fe120417b0d618690f74029004ad474c Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Fri, 25 May 2007 02:46:01 +0000 Subject: [PATCH] hush: we can't do without variable->value member, saving 25 bytes of code and some runtime memory. Rename few variables. --- shell/hush.c | 80 +++++++++++++++++++++++++--------------------------- 1 file changed, 38 insertions(+), 42 deletions(-) diff --git a/shell/hush.c b/shell/hush.c index 0b8e7d68d..f40284cbb 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -286,8 +286,7 @@ struct close_me { #define setenv(...) setenv_is_leaky_dont_use() struct variable { struct variable *next; - char *name; /* points to "name=" portion */ - char *value; /* points directly after "=" */ + char *varstr; /* points to "name=" portion */ int max_len; /* if > 0, name is part of initial env; else name is malloced */ smallint flg_export; /* putenv should be done on this var */ smallint flg_read_only; @@ -334,8 +333,7 @@ static const char version_str[] = "HUSH_VERSION="HUSH_VER_STR; static const struct variable const_shell_ver = { .next = NULL, - .name = (char*)version_str, - .value = (char*)version_str + sizeof("HUSH_VERSION=")-1, + .varstr = (char*)version_str, .max_len = 1, /* 0 can provoke free(name) */ .flg_export = 1, .flg_read_only = 1, @@ -554,8 +552,8 @@ static char **expand_strvec_to_strvec(char **argv); static char *expand_strvec_to_string(char **argv); /* used for expansion of right hand of assignments */ static char *expand_string_to_string(const char *str); -static struct variable *get_local_var(const char *var); -static int set_local_var(char *s, int flg_export); +static struct variable *get_local_var(const char *name); +static int set_local_var(char *str, int flg_export); static void unset_local_var(const char *name); /* Table of built-in functions. They can be forked or not, depending on @@ -831,7 +829,7 @@ static int builtin_export(char **argv) var = get_local_var(name); if (var) { var->flg_export = 1; - putenv(var->name); + putenv(var->varstr); } /* bash does not return an error when trying to export * an undefined variable. Do likewise. */ @@ -976,7 +974,7 @@ static int builtin_set(char **argv) if (temp == NULL) for (e = top_var; e; e = e->next) - puts(e->name); + puts(e->varstr); else set_local_var(xstrdup(temp), 0); @@ -2676,39 +2674,39 @@ static char* expand_strvec_to_string(char **argv) } /* This is used to get/check local shell variables */ -static struct variable *get_local_var(const char *s) +static struct variable *get_local_var(const char *name) { struct variable *cur; int len; - if (!s) + if (!name) return NULL; - len = strlen(s); + len = strlen(name); for (cur = top_var; cur; cur = cur->next) { - if (strncmp(cur->name, s, len) == 0 && cur->name[len] == '=') + if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=') return cur; } return NULL; } -/* name holds "NAME=VAL" and is expected to be malloced. +/* str holds "NAME=VAL" and is expected to be malloced. * We take ownership of it. */ -static int set_local_var(char *name, int flg_export) +static int set_local_var(char *str, int flg_export) { struct variable *cur; char *value; int name_len; - value = strchr(name, '='); + value = strchr(str, '='); if (!value) { /* not expected to ever happen? */ - free(name); + free(str); return -1; } - name_len = value - name; + name_len = value - str; cur = top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */ while (1) { - if (strncmp(cur->name, name, name_len) != 0 || cur->name[name_len] != '=') { + if (strncmp(cur->varstr, str, name_len) != 0 || cur->varstr[name_len] != '=') { if (!cur->next) { /* cur points to last var in linked list */ break; @@ -2716,45 +2714,44 @@ static int set_local_var(char *name, int flg_export) cur = cur->next; continue; } - /* We already have a var with this name */ + /* We found an existing var with this name */ + *value = '\0'; if (cur->flg_read_only) { - bb_error_msg("%s: readonly variable", name); - free(name); + bb_error_msg("%s: readonly variable", str); + free(str); return -1; } - *value = '\0'; - unsetenv(name); /* just in case */ - *value++ = '='; - if (strcmp(cur->value, value) == 0) { + unsetenv(str); /* just in case */ + *value = '='; + if (strcmp(cur->varstr, str) == 0) { free_and_exp: - free(name); + free(str); goto exp; } - if (cur->max_len >= strlen(name)) { + if (cur->max_len >= strlen(str)) { /* This one is from startup env, reuse space */ - strcpy(cur->name, name); + strcpy(cur->varstr, str); goto free_and_exp; } /* max_len == 0 signifies "malloced" var, which we can * (and has to) free */ if (!cur->max_len) - free(cur->name); + free(cur->varstr); cur->max_len = 0; - goto set_name_and_exp; + goto set_str_and_exp; } /* Not found - create next variable struct */ cur->next = xzalloc(sizeof(*cur)); cur = cur->next; - set_name_and_exp: - cur->name = name; + set_str_and_exp: + cur->varstr = str; exp: - cur->value = cur->name + name_len + 1; if (flg_export) cur->flg_export = 1; if (cur->flg_export) - return putenv(cur->name); + return putenv(cur->varstr); return 0; } @@ -2769,7 +2766,7 @@ static void unset_local_var(const char *name) name_len = strlen(name); cur = top_var; while (cur) { - if (strncmp(cur->name, name, name_len) == 0 && cur->name[name_len] == '=') { + if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') { if (cur->flg_read_only) { bb_error_msg("%s: readonly variable", name); return; @@ -2777,9 +2774,9 @@ static void unset_local_var(const char *name) /* prev is ok to use here because 1st variable, HUSH_VERSION, * is ro, and we cannot reach this code on the 1st pass */ prev->next = cur->next; - unsetenv(cur->name); + unsetenv(cur->varstr); if (!cur->max_len) - free(cur->name); + free(cur->varstr); free(cur); return; } @@ -3256,7 +3253,7 @@ static const char *lookup_param(const char *src) { struct variable *var = get_local_var(src); if (var) - return var->value; + return strchr(var->varstr, '=') + 1; return NULL; } @@ -3682,14 +3679,13 @@ int hush_main(int argc, char **argv) if (value) { /* paranoia */ cur_var->next = xzalloc(sizeof(*cur_var)); cur_var = cur_var->next; - cur_var->name = *e; - cur_var->value = value + 1; + cur_var->varstr = *e; cur_var->max_len = strlen(*e); cur_var->flg_export = 1; } e++; } - putenv(shell_ver.name); + putenv(shell_ver.varstr); #if ENABLE_FEATURE_EDITING line_input_state = new_line_input_t(FOR_SHELL); @@ -3827,7 +3823,7 @@ int hush_main(int argc, char **argv) while (cur_var) { struct variable *tmp = cur_var; if (!cur_var->max_len) - free(cur_var->name); + free(cur_var->varstr); cur_var = cur_var->next; free(tmp); } -- 2.25.1